Car struck by lightning safe because it forms a Faraday cage or is it the skin effect

Most places I've read say it's because the car forms a Faraday cage, but a few say that is incorrect and that it's actually from the skin effect. The notable case of the latter explanation is from the Boston Museum of Science: http://www.mos.org/sln/toe/cage.html

This guy, Dr. Davis from the Boston Museum of Science, also is cited all over the place in news articles as stating it's because of the skin effect. Is he right or is pretty much everybody else write and he's wrong?

A detailed explanation would be much appreciated as I've read both sides of the argument and they both seem pretty convincing.